Blackrock Bridge,

The Department's description

Exterior description and setting

A skewed single-span steel deck railway bridge, aligned N-S and carrying the former Londonderry & Enniskillen railway (later the Great Northern) over the Strule River.

The bridge comprises a latticed steel 'trough' supported centrally on a substantial lozenge-shaped tapered pier formed into a V at either side and faced in dressed stone. There is a stone string course above the mid level, above which the stone is rock-faced. The rails are held in place by a series profiled sections riveted to the deck, which further support a steel rail parapet. The bridge terminates with rock-faced stone piers located on the steep banks at either side.

The bridge is located in a rural
setting with grassed banks and open pasture to either side.

Span: Steel
Piers/ abutments: stone

Historical information

‘Blackrock Bridge’ first appears, captioned, on the second edition map of 1852. The railway is captioned ‘Londonderry & Enniskillen Railway’. By the third edition of 1905-6 this has become the ‘Great Northern Railway (Ireland)’. The construction of the present bridge would appear to indicate that it was rebuilt, along with other wooden bridges on the line, in 1910-11.

McCutcheon comments on the development of the railway," The Londonderry & Enniskillen Railway Company was incorporated in 1845, authorised to construct a single-track line of railway extending southwards from a Londonderry terminus…Work began soon afterwards and by April 1847 the single-track line had reached Strabane…The cost of construction was relatively low, about £10,000 per mile…However, due to the shortness of the line, storm damage…and competition from the Strabane Canal and Foyle Navigation, this first section of the company’s line was not a great commercial success. It was not until the construction of the line to Omagh, reached in 1852, Fintona (1853) and Enniskillen (1854) that the full benefits of the railway became apparent. Undoubtedly the new line of rail communication brought important commercial advantages to the towns which it served, and indirectly, to the agricultural lands, both arable and pastoral in character, lying along the valleys of the Foyle, its headstreams and tributaries, and to the flanking upland areas to both east and west. Omagh and Strabane, in particular, emerged as major market centres from which goods could be conveyed northwards to the port of Londonderry. ” (p.109-110)

The Londonderry and Enniskillen Railway eventually amalgamated with other lines, starting in 1860 when it was “leased to the Dundalk & Enniskillen Railway Company, subsequently the Irish North Western Railway Company, for 99 years …The INWR was absorbed by the Northern Railway Company on 1 January 1876 and this in turn merged with the Ulster Railway Company on 1 April 1876 to form the Great Northern Railway Company (Ireland).” (p.110-1)

McCutcheon comments that several original bridges on the line were replaced in 1910-11, “Between Newtownstewart and Strabane, several of the earlier cast-iron girder trellis bridges, which in turn had replaced the original timber bridges put up by the Londonderry & Enniskillen Railway Company around 1850, were themselves replaced in 1910-11 by enclosed troughs of riveted iron sheets supported on massive steel girders e.g.…Breen Bridge…and Camus Bridge”. (p.162) Although Blackrock Bridge is situated along the Newtownstewart to Omagh stretch of the line, comparison indicates that this bridge, too, may have been reconstructed around this period.

During the post-war period the railways faced increasing competition from road transport and in 1953 the GNR ceased to exist as a separate and independent company. “In that year the entire system was acquired jointly by the Governments of Northern Ireland and the Republic of Ireland, and was subsequently operated by a Board consisting of representatives of the two governments. In 1958 the greatly diminished portion of the former Great Northern system which lay within Northern Ireland passed under the absolute control of the Ulster Transport Authority” A period of contraction followed in which many lines deemed to be unremunerative were closed down. (p.119)

References:

Primary Sources

PRONI OS/6/6/17/2 – Second Edition Ordnance Survey Map (1854)
PRONI OS/6/6/17/3 – Third Edition Ordnance Survey Map (1905)
PRONI OS/6/6/17/4 – Fourth Edition Ordnance Survey Map (1936)

Secondary Sources

McCutcheon, W.A. “The Industrial Archaeology of Northern Ireland,” London: HMSO, 1980.

Criteria for listing: architectural interest

A. Style
B. Proportion
C. Ornamentation
D. Plan Form
F. Structural System
J. Setting

Criteria for listing: historic interest

X. Local Interest

Evaluation

Blackrock Bridge is a substantial early-twentieth century steel railway bridge, carrying the former Great Northern Railway over the Strule River. It represents the progression of technology in structural engineering terms, (necessitated by the introduction of improved rolling stock), and the railway is an important part of the industrial development of the district, facilitating trade in the area and improving communication links.